FI71684B - OVER VERIFICATION FOR OVER LIGHTING WITH FASTS - Google Patents

Description

1 71684

Method and tool for removing clink-stuck pieces n

The present invention relates to a mBnBtBlmma for removing stuck bodies such as bolt nuts or the like by means of an arc tool, in which method an electrically conductive tip portion of the tool connected to one pole of the power supply is guided toward the stuck body connected to the other pole of the power supply. in the method, the heat generated by the arc generated between the end of the tip part and the stuck body is used to heat and / or flame cut the stuck body, after which the stuck body can be detached from its attachment object. The present invention also relates to a tool for removing stuck bodies, kutBn bolts, nuts or the like, the tool comprising an electrically conductive tip portion and means for connecting the tip portion to one pole of the power supply and connecting the stuck body to the other pole of the power source and forming an arc between the song.

In accordance with current practice, impact wrenches or hydraulic wrenches are used to open rusted nuts. The disadvantages of such solutions are that the work is physically difficult to perform and that there is a risk of an accident at work at any time. It is also known to use heating to open very awkwardly stuck nuts, in which case the removable nut is heated or flame-cut using gas welding or flame-cutting equipment.

Regarding the disadvantages associated with gas heating, it should be mentioned that the gas cylinders and / or hoses 35 must be transported to a removable object, which is often located in an inaccessible and even dangerous place - e 71684 this is of course undesirable and time consuming. With regard to gas flame heating, it should also be noted that when heating large nuts in hard-to-reach places, the flame can escape, which can damage the flange or machined surfaces associated with the nut and put the worker at maximum risk in the event of a fire.

Non-destructive heating methods are also known to tighten the bolts and / or to allow the trapped bodies to be removed. These heating methods are invariably electric and are based on either resistance or short-circuit heating.

15 SE-A-39539B discloses a heating solution for heating connection bolts, in particular before final tightening of the bolt. According to the publication, it is proposed to heat the bolt by pressing a fixed heating tip cap-20 le with a heating resistor against its end. The most significant disadvantage of the solution is its slowness, which is further accentuated as the part to be heated increases.

SE-A-393762 discloses a time-locked heating solution for heating connection bolts, in particular for heating the flange connection bolts of turbine-25 nipples before opening or tightening the bolts. In the publication, it is proposed to heat the connection bolt so that the terminals of the power supply are short-circuited. via a bolt, in which case the one end of the bolt is connected to the negative terminal of the power supply and the other end 30 to the positive terminal. A similar short-circuit heating solution is also disclosed in DE 1166213, especially for hollow connection bolts, in which case the lower end of the connection bolt is proposed to be connected to one of the poles of the power supply via a 3S current conductor arranged inside the connection bolt. In these solutions, the connecting bolt is thus heated by the eddy currents acting on it.

3,71684

One of the most significant disadvantages of the solutions is that very large electrical currents are required, and thus also large auxiliary equipment, "1 which can make work in cramped spaces impossible.

5

The object of the present invention is to eliminate the above-mentioned disadvantages and disadvantages inherent in the known solutions.

This object is achieved by a method such as that mentioned at the outset, in which the tip part is rotated at least during the heating and / or combustion-cutting step, and by a tool such as that mentioned at the beginning, characterized by a rotatable, electrically conductive shaft mounted inside the tool body part, that the tip portion is releasably attached to the free end of the shaft and locked to rotate therewith.

Among the advantages of the invention, it should be mentioned that the physical implementation of the detachment work is accelerated, which significantly reduces the working time required for the detachment. It should also be noted that no gas flame is required at all, some removal work can be carried out without any problems in connection with various casting structures and machine repairs. During the removal 55 according to the invention, the heat does not rise too high, thus avoiding fire and metal damage. A very important advantage is that it is safe to work in a place prone to fire and explosion, and that demolition work can also be carried out in underwater conditions.

30

The invention will now be described, by way of some preferred embodiments thereof, with reference to the accompanying drawing, which shows a partially cross-sectional side view of a stuck body removal tool according to the invention.

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As can be seen from the figure, the detachable tool according to the invention comprises a rotatable, electrically conductive and spring-loaded tip part E1 and means for conducting the battery to said tip part 51. Preferably, both the tip part 51 and the electrically conductive means 5 are arranged in the tool body part 50.

When using the tool according to the invention, the jammed body 1, in particular the rusted nut-10, is opened as follows: first the electrically conductive tip part 51 is pressed against the removable nut 1, after which an electric potential difference is created between the nut 1 and the tip part 51. to the nut 1, after this the heat energy generated by the arc generates 15a, the nut 1 is heated, which expands due to its thermal expansion, which makes it possible to open the nut 1.

According to the method according to a preferred embodiment of the invention, the tip part 51 is rotated during substantially the entire heating step, whereby not only the heating of the nut 1 but also the combustion of the nut 1 is possible. In this case, it is preferred that the tip part 51 is shaped as an open hollow body at its end and made of a termite material of fusible material. In this connection, it should be emphasized 55 that it is clear to a person skilled in the art of welding that the choice of material can have a decisive effect on the achievable heating or flame cutting temperature.

By using the above-mentioned hollow body as a tip portion 51 30 and dimensioning it to correspond to the threads of the detachable nut, the threads of the stuck nut can be easily burned by flame cutting. Because the tip portion 51 is continuously rotated throughout the heating or flame cutting step, it removes the molten material between the tip portion 51 and the nut 1 throughout its rotational motion. After threading the threads, the nut 1 can be easily pulled off the bolt or the like from its fastening object.

A tool 5 2 according to a preferred embodiment of the invention is constructed in such a way that an axially rotatable shaft 22 is mounted inside the cylindrical body part 20, at the end of which there is a cavity 23, inside which a detachable tip part 21 locked to rotate with the shaft 22 is arranged. and a spring means 24, 10 for loading the tip part 21, preferably a helical spring, which rests on one end of the cavity 23 and on the other end of the tip part 21.

Any suitable power device (shown in the figure) can be used to rotate the shaft 22 and the rotating tip part 21, which can be connected, e.g. by a flange connection, to the shaft 22. Such suitable power devices are e.g. various electrical, hydraulic, pneumatic or mechanical rotating devices.

As already stated above, the tip part 21 is of electrically conductive material, preferably self-combustible when a certain temperature is reached, i. tBrmite, substance. In order to minimize vibrations and to keep the compressive force and the arc between the nut 1 and the tip part 21 as even as possible, the tip part 21 is spring-loaded, whereby the spring 24 continuously presses the tip part 21 out of the cavity 23.

It is immaterial to the invention how the tip part 21 is locked in the axial direction and rotatably with the shaft 22 in the cavity. Such a joint can be constructed very easily by any person skilled in the art. It should be noted, however, that it is advantageous for the effortless use of the tool to use suitable quick-locking means between the on-space 23 and the tip part 21. Suitable means for this purpose are, for example, flexible clamping members which, when fastened to the walls delimiting the cavity 23, press against the outer circumference of the shank part of the tip part 21 working inside the cavity 23, preferably in the grooves formed therein. Thanks to the quick lock, the tip part 21 of the tool 2 can be quickly replaced.

5

In order to burn the threaded part of the nut 1, or the like, the tip part 21 is shaped as a hollow body, most preferably cup-shaped, whereby the helical spring 24 rests on the outer surface of the bottom of the cup-shaped tip part 21. The tip part 21 can also be made of a pipe piece 10, in which case it is necessary to install an electrically conductive metal plate between the helical spring 24 and the tip part 21 for the helical spring 24.

The diameter of the circumference of the hollow tip portion 21 pressed against the detachable nut 1 is selected to correspond to the diameter of the threaded portion of the detachable nut 1 to remove the threaded portion by flame cutting. Since the size of the detachable nuts 1 varies within a wide range, it is advantageous for the smooth operation of the work that tip parts 21 of different diameters can be connected to the tool 2 20 according to the invention. To achieve this goal, all shank parts 21 of the tool body 20 have a shank while the pigs of the end portions Dimen-25 intended to protrude from their cavity space 23, in particular the diameters, gradually vary within wide limits, the tip portions 21 forming a so-called according to a preferred embodiment of the invention, both the annular space 23 and the arm part of the tip-30 part 21 are polygonal in cross section and the end of the tip part 21 is projecting from the cavity 23 of the tip part.

In addition to removing the nuts 1, the tool 35 according to the invention can also be used for heating metal, e.g. in the shipbuilding industry for heating large metal plates. For this purpose 7 71684, a piece is used as the tip part E1, the end of which protruding from the cavity space S3 widens outwards in a cup. In the exemplary case according to Figure 1, the means for conducting electricity to the tip part E1 comprise a connector 30 to which the electric current from the transformer is conducted by means of a cable. The connector 30 is electrically conductive connected to a feed ring 31 arranged concentrically around the shaft SE, of which 10 an electric current is applied to the slip ring 3E, the carbon 33 and the carbon flange 34 in contact with the shaft SS, the end cavity E3 of which is arranged as above. explained the rotating tip portion El along the shaft EE.

According to a preferred embodiment of the invention, the cavity space 53 is filled with an electrically conductive liquid substance, preferably mercury, through which an electric current is conducted from the shaft to the tip part E1. To ensure that the mercury remains in the cavity S3 and e.g. to allow the use of the tool E underwater SO, the adapter between the tip part S1 and the cavity S3 is tight and possibly provided with a seal. In addition, an insulating plate is installed in the cavity space S3 between the coil spring 54 and the bottom of the cavity space S3 to control the supply of electric current and to prevent the coil spring 54 from burning.

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In order to prevent the ingress of fines and also to allow the underwater use of the tool S, the annular space between the tool body SO and the shaft EE is sealed e.g. with a lip seal 4. Especially in fire-prone places, a bellows tube 5 is attached to the SI side end of the body part. encloses the tip portion S1 and the removable nut 1, the tip portion 51 being preferably operated in a liquid-filled space inside the bellows tube 5.

According to a preferred embodiment of the invention, a rotatable sleeve .6 is detachably mounted on the rotating shaft B2 of the 35a 71684, by means of which the nut 1 loosened by heating the tip part 21 can be opened. In this case, the nut 1 is first heated by means of the tip part 21 and when the heat-5 condition rises sufficiently the power supply is cut off and the tool is pushed one step deeper towards the nut 1 or the sleeve B is moved on the shaft towards the nut, whereby the sleeve is placed on the nut 1. In this context, it is also worth emphasizing 10 the fact that the sleeves also come in different sizes in order to find a suitably sized sleeve for each nut to be removed 6.

The invention has been described above only with some embodiments of its BdullistBn 15. Of course, this is not intended to limit the invention, but the details of the invention can be varied considerably within the scope of the appended claims.

Claims (11)

1. A method of loosening fasteners C1), such as bolts, nuts, etc., with a light-tool (S), 5. The method of the tool C2 (electrically conductive tip part C21) which is connected to a pole by a power source is conducted. against the seated piece C1), which should be connected to another pole of the power source, and in which method the seated piece C1) is heated and / or burned with heat energy developed by a light beam which arises between the tip portion C21) end and the seated piece C1), after which the seated piece can be loosened from the point of attachment, characterized in that the spacer part C21) is rotated At least during the heating and / or burning cutting stage. 2. Loose attachment tools (Cl), such as bolts, nuts, etc., which have an electrically conductive tip part C21) and means for connecting the tip part C21) to a pole of a current source and cb for connecting the seated piece C1) to another pole of the current source to form a light arc between the end of the tip portion C21) and the seated piece C1, characterized in that a rotatable, electrically conductive shaft C22) is stored within the tool body portion C20), and the spacer portion C21) is releasably attached to the free end of shaft C22) and readable to rotate with it. A tool according to claim 2, characterized in that in the free end of the shaft C22) there is a cavity (C23), in which is read the tip part C21), and that in the bell space (C23) is an spring means C24) which loads the tip part C21). A tool according to claim 2 θΙΙβγ 3, characterized in that the tip portion C21) is βπ at its open end.